Previous studies have shown that leadership affects the success of the company, but does not sufficiently studied the impact of leadership on the success of the company, if it is measured with Balanced Scorecard system. It is particularly important to explore the impact of leadership on the company due to its size, stage of growth and international orientation. Therefore, the subject of this paper is the impact of leadership on the success of the company measured with the Balanced Scorecard system in the Republic of Croatia. Also, the influence of leadership in international business has not sufficiently stuied. Therefore, this paper systematically, theoretically and empirically examines the impact of leadership on the success of companies measured with Balanced Scorecard system with a focus on international business. The purpose of the research is to identify how different styles of leadership (autocratic, democratic, laissez faire) affects the success of the company, with reference to international business. In order to achieve the objective of the work, the survey was conducted on a stratified sample of Croatian companies. Data collected by primary research were analyzed using descriptive statistics (frequency distribution, contingency tables, measures of central tendency and dispersion measures), as well as methods of inferential statistics (Correlation analysis, regression, factor analysis, Ann's analysis and Cronbach's alpha coefficient). The results showed that different styles of leadership affect the financial, market, process performance, as well as the success of knowledge management companies, whereby it is assumed that this effect is different in terms of size and growth stage companies. Additionally, the effect of leadership styles on the international orientation of the company has been investigated, and it turned out that there is different impact on it. The research results provide an insight into the practice of leadership in Croatian companies and have expanded knowledge of this important area of management. Given the recent Croatian accession to the European Union, in particular it is an important review of the international business, which will provide the opportunity to point out the current opportunities and challenges faced by Croatian companies.